Experiment Hypotheses

Use of CDD increases development productivity

Did the use of testing decrease development time?

This can be meassured by either looking at

Number of compilations

Number of saves

Number of revisions

IDE time

Asking the students

None of the above strikes me as particualry reliable though. Also, it is easy to develop quickly if you do a bad job.
In order to compare apples to apples we must be careful to compare projects with a similar correcntess and completeness. We could use an external test suite to assess correctness, or the grade of the students.

Use of CDD increases code correctness

Is there a relation between code correctness of project (vs. some system level test suite) and test activity?

Measures for test activity:

number of tests

number of times test were run

Number of pass/fail, fail/pass transitions

Developer Profile

How did students use the testing tools.

Are ther clusters of similar use?

What is charactersitic for these clusters?

Meassures:

Aksing students before and after

Are there projects where tests initially always fail resp. pass

How often do they test?

How correct is their project?

I am not completely sure yet what to assess here.

How do extracted, synthesized and manually written test cases compare?

Which tests are the most useful to students?

How many tests are there in each category?

What's the test suite quality of each category?

Were some excluded from testing more often than others?

How many red/green and green/red transitions are there in each category?